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2 years ago

45 The mass of an unidentified metal sphere is 133 grams. Students determine the

Chemistry

1 answer:

Lisa [10]2 years ago

7 0

Answer:

D Cobalt

Explanation:

The volume of the sphere is 40 -25 = 15 cm^3

Density = mass/volume = 133 gm / 15 cm^3 = 8.87 gm/cm^3

which corresponds to Cobalt from the chart

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How do scientist prevent biases from affecting their data?

Tpy6a [65]

Answer:

Answer should be D. Scientists ignore their own person feelings and interpret data objectively.

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3 years ago

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The process though which animals and plants produce offspring

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2 years ago

please hurry! If 3.87g of powdered aluminum oxide is placed in a container containing 5.67g of water, what is the limiting react

VikaD [51]

Answer:

Explanation:

Given parameters:

Mass of aluminium oxide = 3.87g

Mass of water = 5.67g

Unknown:

Limiting reactant = ?

Solution:

The limiting reactant is the reactant in short supply in a chemical reaction. We need to first write the chemical equation and convert the masses given to the number of moles.

Using the number of moles, we can ascertain the limiting reactants;

Al₂O₃ + 3H₂O → 2Al(OH)₃

Number of moles;

Number of moles = $\frac{mass}{molar mass}$

molar mass of Al₂O₃ = (2x27) + 3(16) = 102g/mole

number of moles = $\frac{3.87}{102}$ = 0.04mole

molar mass of H₂O = 2(1) + 16 = 18g/mole

number of moles = $\frac{5.67}{18}$ = 0.32mole

From the reaction equation;

1 mole of Al₂O₃ reacted with 3 moles of H₂O

0.04 mole of Al₂O₃ will react with 3 x 0.04 mole = 0.12 mole of H₂O

But we were given 0.32 mole of H₂O and this is in excess of amount required.

This shows that Al₂O₃ is the limiting reactant

6 0

3 years ago

In the heating curve of an unknown substance, the line labeled C represents what change(s)?

IceJOKER [234]

Answer:

C) Temperature and Kinetic Energy.

Explanation:

Hello there!

In this case, according to the generic heating curve on the attached file, it possible to see that on the point C, whereas the line is diagonal, the temperature increases, but also the kinetic energy increases because the molecules gain energy due to the increase of the temperature. It is important to say that on flat lines, like those on B and D, the phase change takes place and just the potential energy change.

In such a way, we infer that the answer is C) Temperature and Kinetic Energy.

Best regards!